Category Archives: Journal Club

Lunatic Hypotheses or How Quickly Theories Have To Adapt

Last week, in a matter of a few days, two studies came out that brought with them a completely different perspective on our Moon. The first one, published in Nature Geoscience, was about an alternative hypothesis on the formation of our natural satellite. The (now)

Some Earths Like It Hot

Planetary systems form from the same cloud as its parent star. As the cloud contracts under the effect of gravity, the gas acquires more angular velocity. Spinning faster it flattens out into a disk where eventually planets end up forming. This simplistic approach has been

Interstellar Travel Meets The Real Universe

Interstellar travel is about to go from a Sci-fi idea to physical reality, but the jump comes with a series of considerations that fiction writers don’t have to consider. This could work as an introduction for the apparent lack of toilets in Star Trek, but

Testing Relativity With Nothing

There are two big problems with astrophysics, and they are called dark energy and dark matter. Dark energy is responsible for the accelerated expansion of the Universe. Dark matter keeps the galaxies together, and we think it’s made of particles which don’t emit any light.

The Universe’s composition is the same everywhere

The Japanese X-ray satellite SUZAKU has looked at the distribution of gas around the Virgo cluster, a large galaxy cluster close to the Milky Way and the second brightest in X-rays. It discovered that the elements needed to make living organisms, planets and spiced-up stars

The Very Hungry Supermassive Black Hole

We all get the munchies, but when you’re a supermassive black hole (SMBH) your hunger might have dire consequences. And just like that an SMBH has outgrown its galaxy and jumped to the top of the heavyweight objects in the universe.

About 12 billion light years from us, there is a galaxy called CID-947. It has a mass similar to our own Milky Way (about 1000 billion times the mass of the Sun) and it was only remarkable because it had an active galactic nucleus (AGN, i.e. an accreting SMBH).

Lord of the Rings distance pinpointed

As I mentioned in a previous post, there are a few ways to measure the distance of a star in our galaxy. Unfortunately when the Luminosity is unknown and it is too far away to use parallaxes method, we are stumped for ways to estimate the distance.

Once in a while though we get lucky and we have events that allow us to calculate distance in other ways. Circinus X-1 is one of these events. Circinus X-1 is an x-ray binary; an x-ray binary is a system of two stars where material from one companion is accreting on the neutron star, which in turns emits x-rays.

The taming of the screw

I have a mathematician friend who believes that anything that it is mathematically possible exists somewhere in the multiverse. She believes that there are some features that are so beautiful, that it would be a crime if they were simply quirks of the Universal language.

The Big Bang is not going anywhere.

On the 4th of February a paper was published detailing a Universe that didn’t need a Big Bang. While it is very interesting (you can read it here) I find myself once again at odds with how theoretical papers are formulated.

The paper details a mathematical robust way to solve many cosmological conundrums. The flatness problem (discussed in this vlog), the value of dark energy and the nature of dark matter.